(1) The office shall make an annual cost-of-living adjustment to:
(a) an original allowance paid under Section 49-23-305, if the allowance has been paid for at least one year; and
(b) an original payment made to an alternate payee under a domestic relations order, if the payment is to be paid as a percentage of the allowance rather than a specific dollar amount.
(2)
(a) The original allowance shall be increased by the annual increase in the Consumer Price Index up to a maximum of 2.5%.
(b) Annual increases in the Consumer Price Index in excess of 2.5% shall be accumulated and used in subsequent adjustments when the annual increase in the Consumer Price Index is less than 2.5%.
(3) The Consumer Price Index used in calculating adjustments shall be a United States Bureau of Labor Statistics Consumer Price Index average as determined by the board.
(4) The cost-of-living adjustment made under this section may not decrease the allowance.